1. Field of Technology
This application generally relates to mobile wireless communication devices requiring random data for use in normal device operation.
2. Related Art
A need for random data in normal operation of mobile wireless communication devices is now common place. For example, secure encrypted communication requires generation of suitable encryption/decryption keys or the like from time to time. Generation of an encryption key may be required for device content (e.g., e-mail, calendar, memo pad, contacts, etc.). Wireless communication via Bluetooth or other similar techniques may also require random data inputs from time to time. It is also known that random data may be used to wipe non-volatile memory. For example, in order to insure erased data on a hard drive is unrecoverable, a technique of writing random data to the drive may be employed.
There are known techniques for generating sufficiently random data (e.g., by capturing random mouse movements of a user or the like) at a base station (e.g., a user's personal computer) and then may derive a key for communication or alternative purposes. This key may be stored on a communications server, desktop PC, as well as the handheld device. The newly captured random data and/or derived key may be transferred to associated devices from time to time when the need arises.
However, if a mobile wireless communication device is without an external source of renewable random data (e.g., a plug in connection to the user's base or desktop computer), one needs to address the need for sufficiently random data to use in the generation of a random pattern (e.g., for encryption key generation). Typically when the stored key or random data becomes out of date and the user has connected his/her device to a base or desktop computer, they may be prompted to move a mouse around randomly for generation of a new random number pool for use as an encryption key (or to be used in generation of such key).
A problem to address is how to create the same or approximately equivalent randomness for key creation by random motion once the device no longer connects via serial/USB to the user's desktop.
A similar situation can arise with other peripherals or memory cards which attach to the device that require a method of securing data via a randomly generated pattern for encryption key creation, e.g., secure data (SD) cards, multimedia cards, compact flash, smartcards, Bluetooth accessories, etc.